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Suppose that an individual's initials consist of 3 letters of alphabet. Prove that in a large city there are at least two people with the same initials.

Henno Brandsma
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1 Answers1

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There are $26^3$ many types of initials-people; if the city has more than that amount of inhabitants, at least two will fall within the same type. (pigeonhole principle, the tag says it all).

Henno Brandsma
  • 242,131